Hi, I just bought a 2007 ML320 cdi and fuel gauge has been reading full all the time. I have change both fuel pump and is still reading full. I pull out the #5 fuse by the glove compartment to reset the gauge and that did not solve the problem. I don't know if previous owner had this problem before. Can someone please help me on this issue, this is driving crazy. The only thing not change is rear SAM module.

 

once again biff is in change out everything mode----why not get a scan which will determine the fault as you process aint working

 

I did check all fuses and all were good. The scan show 2 code on the fuel system 90DD and 90DB.